Printing mechanism



Dec. 8, 1936. H. H. KEEN I PRINTING MECHANISM Filed Oct. 4, 1955 4Sheets-Sheet l A'i'TORNEY 7 a a I:

will/11111111111)!!! H. H. KEEN PRINTING MECHANISM Filed QGhv 4, 1935 aI INVENTOR Ai'TORNEY 4 Sheets-Sheet 2 Dec. 8, 1936. H. H. KEEN 2,063,508

PRINTING MECHANISM INVENTOR ATTORNEY Dec. g, 1936. H. H. KEEN 2,063,508

PRINTING MECHANISM Filed Oct. 4, 1935 4 Sheets-Sheet 4 RPM ymww i; BY

A'TToRNEY Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE PRINTINGMECHANISM York Application October 4, 1935, Serial No. 43,538 In GreatBritain October 23, 1934 5 Claim.

This invention relates to printing mechanism arranged for control byrecord cards of the kind in which each column is divided'into two partsand tin which some 01' the characters which are to be printed arerepresented each by a single hole in the column and others arerepresented by pairs of holes, one hole being in one part oi the columnand the other hole in the other part of the column in accordance with acode. Each column may be conveniently divided into a main partcomprising ten hole positions and a subordinate part comprising two holepositions, so that any one of thirty-two characters can be representedin a column.

For convenience it will be assumed that the characters are representedon the card by holes punched therein, but the present invention is alsoapplicable to printing mechanism in which the characters are representedby marks made on the card in selected positions and which are read bylight-sensitive devices in a known manner. V I

More specifically the present invention relates to printing mechanism ofthe kind comprising two. controlling members which are reciprocated andwhich are each arrested, as they move from a home position, in aposition determined by the position of a hole in an associated part of acolumn of the card. Thetwo controlling members are arrested by meanscontrolled by a card-reading device and jointly determine the positionof a setting member in accordance with the positions in which they arearrested. The setting member serves to position a type-carrier which isprovided with type for printing the various characters. One of thecontrolling members operates to make a coarse adjustment of the settingmember and, therefore, of the typecarrier, while the other operates toefiect a fine adjustment by moving the setting member relatively to thefirst controlling member through one or more units of movement which aresmaller than the units of movement imparted to the setting member by thefirst controlling member.

It has been proposed to provide means for locking the setting member tothe first controlling member in any one of a number of positions and toemploy the second controlling member to determine the position in whichthe setting member will be locked to the first controlling member, thesetting member moving with the first controlling member when the latteris adjusted. It has also been proposed to connect the two controllingmembers to the setting member by differential gearing so that theyjointly t mine the position of the setting member. Hitherto in mechanismof this kind, the typecarrier has been secured to the setting member.Owing to the large number of type to be accommodated on thetype-carrier, the latter has to be of relatively large dimensions and tohave a relatively large stroke. The stroke and dimensions of the settingmember will be correspondingly large and the stroke of the firstcontrolling member will be at least as large. it the controlling membersare connected to the setting member by differential gearing the strokeof the first controlling member will be larger than that of the settingmember.

It is desirable to keep the strokes of the various parts of themechanism as short as possible and also the dimensions of the parts,which are partly dependent on their stroke, as small as possible, inorder to reduce the inertia eilfects and allow of the mechanism beingoperated at a high speed. Further any reduction in the dimensions of theparts is advantageous since it tends towards a compact structure. Itwill be obvious that the stroke of the type-carrier cannot be reducedsince it is determined by the number of type it carries, but it is theobject of the present invention to provide printing mechanism of theabove kind wherein the stroke and dimensions of the various parts, otherthan the type-carrier, are reduced as compared with prior mechanism ofthis kind.

The present invention provides printing mechanism of the above kindwherein the setting member is connected to the type-carrier bymovement-increasing gearing so that the stroke of the setting member isless than that of the type-carrier and the controlling members havecorrespondingly reduced strokes.

Preferably, the two controlling members are connected to the settingmember by difierential mechanism which may comprise a differential leverfulcrumed on the two controlling members or parts moved thereby andhaving the setting member pivoted on it.

Conveniently the type-carrier is in the form of a wheel to which apinion is secured and this pinion meshes with-teeth formed on thesetting member which is mounted to reciprocate substantially in astraight line.

With the arrangement according to this invention, any error in theadjustment of the setting member is magnified in the adjustment of thetype-carrier. It is accordingly another object of the present inventionto provide the type-carrier with a set of teeth and to provide ajustifying 55 element movable after the type-carrier has been set toengage between a pair of teeth and accurately position the type-carrier.

The printing mechanism according to the present invention may beemployed in combination with the printing mechanism adapted to printnumerals only and of the known kind comprising a plurality ofreciprocating type-bars and means for differentially arresting themunder the control of a record card. According to this feature of theinvention the first controlling members are designed to havesubstantially the same stroke as the type-bars of the numeral printingmechanism and common means is provided for reciprocating the firstcontrolling members and the numeral printing type-bars.

Printing mechanism embodying the above and other features of the presentinvention will now be described with reference to the accompanyingdrawings in which:-

Figure 1 is a cross-section through the printing mechanism showing theparts in their normal home position,

Figin'eZisasimiIarsectiQntoFigure lbut shows the parts in the positionoccupied at the moment of printing,

Figure 3 shows atically driving mechanism for the printing mechanism,

Figure 4 is a simplified circuit diagram for the printing mechanism, and

Figures 5 and 6 illustrate the manner in which printing is effected.

Like reference characters indicate like parts in all the figures of thedrawings.

Alphabetical and numerial printing mechanism according to the presentinvention will be described as applied to a record-card-controlledstatistical machine of the well-known Hollerith kind such as that shownin U. S. patent to C. D. Lake et al. #1,976,61'7 dated October 9, 1934.The printing mechanism is provided in addition to the usual printingmechanism which prints numerals only. Since the construction andoperation of this kind of statistical machine and of the numeralprinting mechanism provided in it are well-known, they will not bedescribed herein.

Referring to Figure 3, the machine is provided with a list shaft l0(corresponding to list shaft I65 in the above mentioned patent) on whicha list cam II is rotatably mounted. This cam can be coupled to the shaftIII by a one-revolution clutch of conventional construction so that thiscam operates whenever the clutch is engaged. The clutch is engaged inany cycle of the machine, in which the printing mechanism is to operate,in a well-known manner which need not be described. A gear-wheel I2 issecured to the cam H and drives a gear-wheel l3 secured to a shaft l4.This shaft, through bevel gearing l5, drives a shaft l6 which throughbevel gearing drives a shaft IS. The shaft I8 thus rotates at such timesas the cam H is rotating and serves, as will be explained hereinafter,to operate the alphabetical section of the printing mechanism inconjunction with the cam The cam through a suitable lever not shown,reciprocates a cross-head 20 on guides 2| which are mounted in fixedframe members 22. A plurality of first controlling racks 23 aresupported in the cross-head 20. The lower ends of these racks are guidedin slots in a cross-bar 24 and the upper ends in slots in the upperframe member 2!. Lugs 25 on the lower end of the racks 23 are heldagainst the cross-member 24 by levers It which are pivoted in a bracket21 and are pulled upwardly by springs 28. Thus, as the cross-head rises,the racks 23 will also rise. Each of the racks can be arrested in anyposition, as it rises, by energizing a rear print magnet RPM. whenenergized, this magnet rocks a latch II to unlatch a pawl 30 whichengages one of ten teeth 3| on the rack. The rack is then held while thecross-head continues its upward movement, the springs 28 stretching topermit this.

The cross-head II also carries a plurality of type-bars in the numeralsection of the printing mechanism. These type-bars are of conventionalconstruction and are similar to the racks 23 except that they areextended upwardly to the level of a platen 32. Each type-bar carries atype-head at its upper end. The type-bars are arrested in the same wayas the controlling racks 13 by pawls 30 which are released when theprint magnets are energized. As this printing mechanism is well-known itneed not be described in detail. Suitable mechanism, not shown, isprovided for relatching the pawls l0 behind the latches 2! when thecross-head 2| moves downwards towards its home position. As thismechanism is well-known and has no part in the present invention, itwill not be described.

The shaft l8 rotates whenever the cam rotates and the printing mechanismis in operation, as previously explained. This shaft carries a pair ofcomplementary cams 33 and 34 which rock a double-armed lever 35 securedon a shaft 36. A pair of levers I! are secured on the shaft It andengage, at their upper ends, a cross-head 38. The cross-head a issupported on guide rods 38 which, in turn, are carried by frame members40. The timing is such that the levers 35 and 31 and the cross-head 38remain stationary during the first part of the upward movement of thecross-head 20. During approximately the last third of the upwardmovement of the cross-head 20, the levers 35 and 31 are rockedcounter-clockwise and move the crosshead 38 to the left into theposition shown in Figure 2. The two cross-heads are restoredsimultaneously from the position shown in Figure 2 to that shown inFigure 1.

A plurality of second controlling racks 4| are supported at one end inslots formed in a member 42 which forms part of the cross-head 4|. Attheir other ends the racks 4| are supported in slots formed in a fixedframe member 43. The racks 4| are pressed to the left so that lugs 44 onthem engage the member 42 by levers 45. These levers are pivoted in abracket 46 and pulled to the left by springs 41. The racks 4| will thusmove with the cross-head 38 to the left but can be individuallyarrested, the springs 41 yielding so that the cross-head can continueits movement without the racks.

Each of the racks 4| can be arrested in either of two positions byenergizing anassociated front print magnet FPM which then rocks a latch48 to release a pawl 49. This pawl engages one or other of two teethlabelled X and Y in Figure 1, depending on the time when the magnet wasenergized. The pawl 49 is relatched by a high tooth 50 when thecross-head 38 moves back into the position shown in Figure 1.

If one of the magnets FPM is not energized, the corresponding rack 4|moves to the left until it engages an adjustable stop 5| as shown inFigure 2. The second controlling rack 4| can thus be arrested in any oneof three positions as it moves to the left. If one of the magnetsaooauoa RPM is not energized, the associated rack 23 moves until engagedby an adjustable stop 52. Each rack 23 can thus be arrested in any oneof ten positions by energizing its magnet RPM at the appropriate timeand in an eleventh position, if this magnet is not energized.

The standard Hollerith record-card has twelve hole positions in acolumn. The hole positions are designated Y, X, 0, 1 8 and 9, readingfrom top-to bottom. Each column may be regarded upper part comprisingthe X and Y" positions and the lower part the "0 to 9 positions. I Eachof the magnets RPM is energized at a time determined by the position ofa hole in the lower part of a column while the corresponding magnet FPMis energized in accordance with the position of a hole in the upper partof the column.

The numerals and the letters of the alphabet are represented by holes inaccordance with the following code:-

-o12a4cc7eo xanc'nar'nrxnm r znroa'ruvwxr 0123456789 13 to M if there isa hole in. one of the 0 to "9 positions, as shown in the top line of theabove table. In the same way, a hole in the "Y position represents oneof the letters in the second line in accordance with the position of thehole in the lower part of the column.

Referring again to Figure 1, each pair of first and second controllingracks 23 and 4| controls the position of a setting rack 53. This rack ispivoted at 54 on a differential lever 55 which is fulcrumed at I55 onling rack 23. The lever 55 carries a pin 56 which rides in a slot 51 ina lever 58 which is pivoted at 59. The associated second rack 4| carriesa pin 55 which engages a slot 5| in a lever 52.

This lever is also pivoted at 59 and is adjustably secured at 53 to theassociated lever 58.

, The rack 53 is provided with teeth 54 which mesh with a pinion 55secured to a type-wheel 53. Each pinion 55 and. the associated typewheel55 rotate on an individual bushing 51 which is non-rotatably supportedon a bar 55. The type-wheel 551s provided with thirty-three type roundone half of its periphery. The type are arranged in the order shown inthe above table, starting at A and reading down each column in turn.Thus the type reads A, Z, B, N, 0, etc., the A type being to the left ofthe wheel as seen in Figure 1. As the first controlling rack 23 rises,the differential lever 55 rocks about its pivot 55 and raises thesetting rack 53 which rotates the type-wheel 55. The arrangement is suchthat a movement of the rack 23 equal to the pitch of the teeth 3| turnsthe wheel 55 to carry three of the type past a platen.

as being divided into two parts, the

the associated first controlally,

| a Each of the teeth 3| correspondsto one of the digits 0 to 9 and whenthe rack 23 is arrested by the pawl 30 engaging one of the teeth 3|, thecorresponding type-wheel 55 will be arrested in a position determined bythe position in which the rack was arrested. Since each tooth 3|corresponds to a digit it also corresponds to one of the type on thewheel 55. The arrangement is such that when the rack 23 is arrested, bythe pawl 30 engaging a particular tooth 3|, say the 5" tooth, the wheel55 is positioned with the type for printing the next lower digit, forexample, in the case suggested, the 4" type, approximately opposite theplaten 32.-

Concurrently with the latter part of the movement of the cross-head 20,the second controlling racks 4| are moved to the left until arrested bythe pawls 49 or by the stops 5|. As each rack moves, it rocks thecomposite lever 53, 52 and rocks the differential lever 55 about itspivot I55 on the associated rack 23. As the lever 55 rocks about itspivot I55 it draws the setting rack 53 downwardly. The rack 53 thenrotates the associated type-wheel 55 backwardly. The arrangement is suchthat if a rack 4| moves its full stroke to the left, it will rotate thewheel 55 through approximately three type spaces. Since each rack 4| canbe arrested in any one of three positions, it can rotate the associatedwheel 55 backwardly through one, two or three type spaces so as to bringopposite the platen 32 one of the three type immediately following, in aclockwise direction, the type which was positioned opposite the platen32 by the associated first controlling rack 23.

Each first controlling rack 23 thus efiects a coarse adjustment of theassociated type-wheel 55 while the corresponding second controlling rack4| effects a fine adjustment by turning the wheel backwardly one, two orthree steps.

Assuming that the slot 51 is horizontal the pivot 54 would movevertically with equal steps as the rack 23 moved up with equal steps.The pivot 54 would also move first to the left and then to the rightalong a curved path, as the lever 55 turns about its pivot i56. Sincethe pivot 54 is to the right of the vertical through the point at whichthe rack 53 meshes with the pinion, the movement of the pivot 54 to theleft will accelerate the clockwise rotational movement imparted to thewheel 55 by the setting rack 53 and movement of the pivot 54 to theright will decelerate the movement of the wheel.

There is thus a tendency for the ratio between the speeds of the rack 23and wheel 53 to decrease as the rack rises. This tendency is overcome bythe fact that the slot 51 is normally inclined as shown in Figure 1. Asthe pivot 55 moves to the left, the pin 55 moves to the left down theslot 51 and is depressed proportiondecelerating the movement imparted tothe wheel. When the pivot 54 and the pin 55 move to the right, the pinis raised by the slot and the movement of the wheel is accelerated. Theslope of the slot is selected to provide approximately the requiredcompensation.

A similar effect occurs when the lever 55, 52 rocks, but here movementof the pin 55 to the left in the slot 51 occurs when the movement givento the wheel 55 is decreased and to the right when the movement isincreased. The slot 51 is non-radial with respect to the pivot 59 of thearm 55, so that movement of the pin 55 to the left increases themovement imparted to the lever 55 and hence to the wheel 55, whilemovement to the right decreases the movement imparted to the wheel.

The shaft 68 is supported in a frame comprising a pair of arms 18pivoted at II and connected together at their upper ends by a bar I2.The frame is held against adjustable stops I8 by springs I4. Each of thesetting racks 53 is held against its pinion 65 by an individualspring-loaded plunger 15, the plunger I5 being carried in a suitablespring-box I6 which is secured to the bar I2. After all the wheels 66have been positioned, the frame 18, I2 is rocked about its pivot II by apair of cam elements II which are secured on wheels I8 and which engageprojections 18 on the arms I8 as shown in Figure 2.

The wheels are thus pressed against a suitable ink ribbon which makes animpression on paper passing around the platen 32. The bushes 61 are freeto slide on flats formed on the shaft 58 to a limited extent. Normallythe spring plungers I5 operate to maintain the bushes 61 and shafts 68in the relative position shown in Figure 1. When, however, the wheels 66are moved to the left to make an impression, they are arrested as soonas they engage the platen 32 while the shaft 68 moves further to theleft into the position shown in Figure 2. The pressure for effectingprinting is supplied by the springplungers 15 acting through the settingracks 53 .and the pinions 65. This arrangement is provided to preventrisk of the type being damaged during the actual printing operation. Therack 53 and pinion 65 provide a movement-increasing gearing so that thetotal linear movement of any type on the wheel 66 is greater than thetotal movement of the rack 53. Consequently, any error in the setting ofthe rack 53 will result in a magnified error in the setting of the wheel66. In order to correct any such errors, justifying mechanism isprovided for aligning the type wheels 66.

Each of the type wheels is provided, round one half of its periphery,with teeth 88, the gaps 8i between the teeth being each diametricallyopposite one of the type. Justifying elements 82 are pivoted on a rod 83and co-operate each with one of the type wheels 66. The rod 83 issupported by two plates 84 which are pivoted by means of adjustableeccentric pivots 85, one on each of the arms I8. The two plates aresecured together by a cross-member 86 and tails 81 of the elements 82are held against this cross-member by springs 88.

An arm 89 is secured to the assembly 84, 86

and a spring 88 is connected to this arm at one end and to one of thearms 18 at the other end. This spring rocks the assembly 84, 86counterclockwise so that an abutment 8| secured on the assembly engagesan adjustable stop 82. The stop 82 is adjusted so that teeth 93 on topof the justifying elements 82 are just clear of the teeth 88 on thewheels 66.

After the wheels 66 have immediately before the cam elements 11 engageand rock the arms 18 to effect printing, a pin 84 secured on a wheel I84 engages a cam surface 85 and rocks the assembly 84, 86 clockwiseabout the pivots 85. The justifying elements 82 will thus rock togetherso that the teeth 33 enter gaps 8| opposite them. The arrangement issuch that the upper side of each tooth 93 tends to engage the undersideof the tooth 88 which happens to be immediately above it (see Figure 5).After this engagement has taken place, the

been positioned and corresponding element 82 rocks about its pivot 88while the assembly 84. 86 continues its movement.

After this has occurred, the arms I8 are rocked about the pivots II. Asthe arms I8 rock each setting rack 58 will also rock about its pivot 54.During this movement the rack 58 rises relatively to the pinion 65 androtates the latter and the wheel 66 clockwise. During this clockwisemovement of the wheel the element 82 is rocked by its spring 88clockwise and its tooth 88 enters fully into the gap between two of theteeth 88. It will be noted that the upper surface of the teeth 88 issubstantially radial to the wheel 66 so that the tooth will, by preventfurther rotation of the wheel 66.

The clockwise movement of the wheel 66 which is a consequence of thearrangement shown is thus made use of to ensure that the tooth 88 shallbe properly seated in one of the gaps between the teeth 88. If, afterthe wheel 66 has been finally located, there is any tendency for itstill to rotate clcckwise, this is taken care of by a slight downwardmovement of the rack 28.

The shaft I8, through gearing 86 and 81, drives a vertical shaft 88which, through gearing 88, drives a shaft 188. This shaft operates knownhammer-actuating mechanism for the numerical section of the printingmechanism. This hammer-actuating mechanism need not be described. Theshaft I I8, through gearing I8I, drives a gear-wheel I82 which isrotatable on a shaft I83. The gear-wheel I82 can be coupled to the shaftI83 by a one-revolution clutch I84 net PCM. The shaft I83 engaging thesurface, A

and m of the alphabetical section. It will be recalled that these wheelsbring about the actual printing by the type-wheels 66. The magnet PCM isenergized atthe proper time in each cycle in which alphabetical printingis required in any suitable manner, not shown herein. In such cycles asthe printing mechanism is re-- quired to operate without thealphabetical section printing, no circuit is completed through themagnet PCM so that the clutch I84 remains disengaged and the shaft I83is not driven. Thus, the magnet PCM would not be energized dur-' ing atotal printing cyc Referring now to Figure 4, there will now bedescribed the manner in which the magnets RPM and FPM are energizedunder the control of the cards. Each card is fed downwardly from amagazine, first past a row of upper brushes U3 and then, one cyclelater, past a row of lower brushes LB. For this purpose card feedingmechanism of conventional construction is employed such as shown in thepreviously mentioned U. S. patent. At the moment when the X holes in acard are passing the upper brushes, cam contacts II8 close so that ifthere is an X" hole in the card a circuit will be completed through theupper brush reading the column containing that hole, normally closedcontacts IIIa, one winding X of a double-wound relay, the contacts H8and upper card lever contacts UCL which are closed in a known manner aslong as a card is passing the upper brushes. The relay X is thusenergized and closes its contacts XI so as to complete a circuitextending through its holding winding Xh and cam contacts II2. Thesecontacts remain closed until the zero holes on the same card pass thelower brushes. The relay winding. Xh thus remains aoeaaoe energized forthe same periodv and holds contacts X2 closed until the same time.

When the rack ll (Figure 1) has moved'sumciently to the left to bringits tooth X opposite the nose of the pawl 49, cam contacts H3 close tocomplete a circuit through the print magnet FPM, the contacts X2 and thecontacts H3. The magnet FPM then arrests the type-bar in the "1!position. This occurs while the card in question is passing the lowerbrushes.

As the card passes the lower brushes, a circuit iscompleted through thelowermost hole in the column in; question, the corresponding lower brushand the magnet RPM. If there is a hole in one of the positions f0 to 9the magnet RPM will be energized and will arrest the associated rack 23in its corresponding position. If there is no hole in one of these twopositions, the rack will move until arrested by the stop 52. Thus, bythe zero time in the cycle in which the card passes the lower brushes,both the racks will have been positioned.

If there is no X hole in a particular column, the circuit previouslytraced through the upper brushes and the relay winding X will not becompleted. Immediately after the "1! holes tacts Illa are opened andcontacts lllb are closed, connecting relay coils Y to the upper brushes.As the "Y" holes pass the upper brushes, cam contacts H8 close so thatif there is a "Y" hole in the particular column in question, a circuitwill be completed through this hole, the appropriate upper brush, thecontacts lllb; the relay coil Y, the cam contacts 5 and the contactsUCL. The coil Y closes its contacts Yl to energize a holding coil Yh andalso closes contacts Y2. The coil Yh is held energized by the contactsH2 until the zero time in the next cycle. When the Y" tooth on the rackis opposite the nose of the pawl 49 (Figure 1), cam contacts H6 close toenergize the magnet FPM through the contacts Y2. The rack ll will thusbe arrested in the Y position.

If there is neither an "X" nor a "Y" hole in a particular column, nocircuits will be completed through the upper brush reading that columnand the magnet FPM will not be energized. The rack M will then move tothe position shown in Figure 2.

At the end of a cycle cam contacts ill close to energize a relatchingcoil 8. The contacts Illa and lllb are normally latched with thecontacts llla closed. The function of the coil III is to unlatch them atthe appropriate time so that they reverse their condition. The coil H8operates to relatch them in their normal condition.

Assume that the column of .a card has a single hole in the 9 position.When this card passes the upper brushes no circuit is completed throughthe upper brush reading the column in question. When the card passes thelower brushes, a circuit is completed through the hole and the magnetRPM so that the pawl 30 (Figure 1) engages the uppermost tooth in therack 23. Initially the type-wheels are positioned with the gap betweenthe M and Y type opposite the platen. The slight upward movement of therack 23 rotates the type-wheel until the 8 type is approximatelyopposite the platen. Towards the end of the cycle the cross head. 38

(Figure 1) moves to the left and the particular rack ll in questionmoves until arrested by the step ii. This willresult in the type wheelbeing rotated through slightly more than three type spaces 'so as tobring the "9 type just above the printing line, as shown in Figure 5.The justifying elements 82 are then rocked and the tooth 93 on one ofthem engages in the gap 8| opposite the 9" tooth. The arms I0 are thenthe type-wheel through slightly more than one type space so as to bringthe "M type lust above the printing line. During the printing movementof the type-wheels this type would have been accurately positioned. Inthe same way, a "Y and a 9 hole result in the "Y" type being brought tothe printing position.

When the type bar 23 is arrested in the position shown in Figure 2 asthe result of there being a zero hole in the card, the operation issimilar except that the rack 23 will still be rising when the rack 4|moves to the left. Thus,'for ashort time the movement of the type-wheelwill be the result of the joint movement of the two racks.

If there is no hole in one of the positions "0? to "9 the rack 23 risesto its highest position and either the type A" or the type Z or the typewill be selected for printing in accordance with the position in whichthe rack ll is arrested. The type is selected if both the racks move totheir full strokes. This type is provided since the type wheel will moveuntil some part of it engages the platen, and serves to prevent animpression being made from the top and bottom of the two adjacent types.The result of providing this type is that the words printed will beseparated by full-stops and. all blank spaces in a line of letters willbe fllled in with dots;

While there has been shown and described and pointed out the fundamentalnovel features of the invention as applied to a single modification itwill be understood thatvarious omissions and substitutions and changesin the form and details of the device illustrated and in its operationmay be made by those skilled in the art without departing from thespirit of the invention. It is the intention, therefore, to be limitedonly as indicated by the scope of the following claims.

What is claimed is:

1. In a printing machine, a pair of type setting bars, means foradjusting said bars, a bell crank operated by one of said bars, adifljerential link with one end pivoted on the other of said bars and atthe other end connected to said bell crank, a rack pivoted on said linkand moved a distance which is the resultant of the combined movement ofthe bars, a type carrier operated by said rack, a. platen, and means forimpressing the type against the platen.

2. In a printing machine, a pair of type setting bars, means foradjusting said bars differentially, a bell crank one end of which ispivotally connected to one of said bars, a differential link carrying afulcrum stud, said link being pivoted at one end on the other of saidbars and at the other end carrying a pin fitting in a slot in said bellcrank, said slot being normally inclined to compensate for the arcuatemovement of said stud, a rack pivoted on said stud, a type carrieroperated by said rack, and means for printing from said type carrier onrecord material.

3. In an alphabet printing machine, a digit bar adjusted diiferentiallyaccording to a digit entry, a zoning bar adjusted diiferentiallyaccording to one of three possible zoning entries, a link withconnections to both bars so that at one end it is lifted by the digitbar and at the other end it is lifted by the zoning bar, a type carrierwith a series of spaced type, a rack for setting said carrier in aposition to print from a selected one 01' said type, said rack beingoperated by said link and pivoted thereon near the connection to thedigit bar so that one step of movement of the digit bar causes threetype spaces of movement on the carrier, and each step of movement of thezoning bar causes a movement oi. a single type space on the carrier, andmeans for printing from the type carrier on record material.

4. In a printing machine controlled by record cards, a pair of typesetting bars, means under control of the cards for setting said bars, adifferential link with connections to said bars so arranged that one endof the link is moved by one bar and the other end of the link is movedby the other bar, a type carrier, a rack for moving said type carrier toprinting p sition, said rack being connected to said link to be moved bythe combined action 01' both bars, and means for printing from said typecarrier on record material,

5. In an alphabet printing machine controlled by record cards perforatedwith regular digit perforations and special zoning perforations, a digitbar, means under control of the digit perforations for adjusting saiddigit bar, a zoning bar, means under control of said zoning perforationsfor adjusting said zoning bar, a differential link with connections tosaid bars so that each end is moved by one of said bars, a type carrierwith aseries of type, a carrier operating rack pivoted on said link atsuch a point that one step of movement caused by the digit bar moves thecarrier through a number of type spaces greater by one than the numberof type space movements caused by adjustment of said zoning bar, andmeans for printing from said type carrier on record material.

HAROLD HALL KEEN.

